There are many things that could cause a car to stall. Fortunately, this usually does not signal a major repair to your vehicle, and it can generally be fixed through some relatively minor adjustments or repairs.

Steps

1

Consider the complexity of your car before beginning and take your car to a trusted repair shop. Modern cars (mid-nineties or later) have an ignition and fuel system that are in large part computer controlled, and it will be difficult for you to make any adjustments. You will want to take it into the shop to address this problem.

2

Check for check engine lights or maintenance required lights on the dash board instrument cluster. Any fuel or ignition problem in modern CPU controlled engine systems will likely cause a code to be displayed, a check engine light, or maintenance required light to come on. If you are not able to use a scan tool, or don't have access to one, many auto parts retailer offer the use of one free of charge.

3

The stall is likely caused by either a problem in the electrical system or in the fuel system. Your engine stops running because it is not igniting fuel in the cylinders. This occurs either because there is not any gas to ignite, or because it lacks the electrical charge to ignite it.

Note that older, carburetor type fuel systems may have too much fuel entering the cylinders, a condition known as flooding.

4

Drive the car up and down steep hills. Does this change the performance of the engine, or cause it to stall? This might indicate a clogged fuel filter. Replacing the fuel filter can often be relatively cheap and easy once you find out where it is located.

Note that some vehicles have fuel filters located in the gas tank, and can be very difficult to access.

Diesel fuel filters and multi-fuel filters can cost over $100.00, U.S.

5

Does the car idle roughly and stall when at idle? If your car has a distributor, you may need to adjust the timing. With the right tools and know how, this is an easy and free task. If your vehicle has fuel injection, you can check the injector by using a screwdriver or mechanics scope. The injectors will make a clicking/snapping sound if working. No sound may indicate a bad injector. It could also indicate an electrical failure with the circuit that drives the fuel injector. Also, check the Ignition Control Module, which controls the timing of the voltage going to spark plugs, and supplies the spark to ignite the fuel/air mixture.

6

If your car has a distributor, you might consider changing the cap, rotor, wires and plugs. This is effectively a tune-up. This can usually be done even by a relative novice to car repair, and take a couple of hours with the right tools. It seems counterintuitive, but even the wires and distributor decay over time, and transmit less electricity. This tune-up may solve your stalling problem — even if it does not, your car should run better and get better mileage afterwards.

7

If your car diesels when you turn off the ignition, it means that your car most likely has a carburetor and the idle speed adjustment is too high. Dieseling describes the situation where you turn off the key, yet the car continues to run for a few seconds or longer, eventually sputtering to a stop. This does not occur on fuel-injected vehicles because when the ignition is turned off so is the fuel supply to the engine as well as the spark plugs.

8

In rare cases, your car may stall due to what is commonly called a "vapor lock," a situation that occurs when the fuel lines supplying gas to the engine become hot enough to boil the gas in the line turning it into vapor. Fuel pumps are designed to pump liquid not “vapor” and thus fail to provide enough fuel pressure. However, a clogged fuel tank vent system can cause a vacuum in the fuel line that causes fuel to eventually stop reaching the engine. This also is a problem unique to carbureted engines. Fuel injected engines commonly have "closed loop" fuel delivery systems that make this condition unlikely to occur. Try opening your gas cap. If you hear a "whooshing" sound, like when you open a can of coffee, it means the gas tank is not venting properly. Now try starting the car. It should work after a couple tries. This is usually found only in older cars. If you have it, this will probably happen again, so your tank vent system should be checked for blockage. More often than not, the problem can be traced to a cheap replacement locking gas cap. A cheap fix is to drill a small hole in your gas cap to allow air in and prevent the vacuum from forming, but the gas cap should not be left this way.

If you turn the ignition to the II position and no lights appear on the dashboard, your battery needs changing (but also check the alternator, as it might not be charging the battery). If the lights show on the dashboard, the starter motor needs replacing.

I recently used some Stop Leak and recharged the AC system after not using it for a year. Now, while driving, if I shift into neutral (standard transmission), the RPMs drop to below 500 and the car will intermittently stall out completely. How can I troubleshoot?

wikiHow Contributor

Disconnect the AC compressor at its plug. If the problem goes away, the idle speed may need increasing to compensate for loading from the AC.

When I stopped at a red light, my car completely stalled. The engine, oil and battery lights were lit on the dashboard. I turned the ignition to the off position and restarted my vehicle, and the engine turned on. It happened about 3 times within 20 minutes. What could do this?

wikiHow Contributor

Possibly a clogged fuel filter. Make sure you have a clean carb. Replace the air filter. If that does not correct the problem, you need an engine tune up: spark plugs, distributor cap, and rotor.

Buy a fuel pressure test kit and plug it into the fuel access valve test port (located somewhere in the engine), crank the engine and see if any pressure reads on the guage. If not, your fuel pump needs replacing.

My car acts up every time I put gas in it. It won't start up till I give it some gas and try to hold idle. If I take my cap off it quits, too. Could you give me some ideas on where to start looking?

wikiHow Contributor

Sounds like the cap is plugged (unless it is an older vehicle). Most newer cars have vented gas caps to keep them from vapor locking. If the system can't vent, the gas doesn't flow. Think about a gas can with the vent hole. If you plug the hole, gas barely comes out; unplug it, and gas flows freely. Stepping on the gas pedal probably gets the fuel moving and lets the engine start. I would replace the cap for sure.

I have a 2002 Hyundai Santa Fe. It's fine on startup, but once it warms up, the engine starts to backfire and not take the gas and the car won't pick up speed. What's wrong?

wikiHow Contributor

It sounds like a head gasket issue. Did the vehicle get hot/overheat before this issue started? It could also be a faulty thermostat. Cars are designed to run at optimal temperatures. If a vehicle gets too hot, it will die.

Why does my car stall after I get gas and while I am using the car radio?

wikiHow Contributor

You should have your car diagnosed by a proper mechanic or technician, but it sounds like a low battery issue. Try turning off the radio, air conditioning or any other optional electronic and then startiing the car.

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Video

Tips

If you can find a friend who knows how to work on cars, ask them to teach you how to do these things.

Certain modern cars may stall on hot days due to the fuel pump. The fuel pump is located at the back of the gas tank, and is cooled by the gasoline itself. On hot days where the car has been running for a while, the fuel pump may overheat and stop working, stalling the car. To prevent this issue, always keep the gas tank at least 3/8 full, or else you might find yourself calling a friend to bring you a gas can!

Tune-up: most people do not know that a tune-up has changed entirely since the days of points and condensers. Now, besides spark plugs and fuel filters, Oxygen sensors should be replaced at 100k miles. This alone will improve fuel economy more than anything besides tire inflation. They will cause stalling as well if they are not functioning correctly. Another very important thing to check is to see if the Mass Air Flow sensor is dirty. This will cause poor performance and possible stalling. They can be cleaned with mass air flow sensor cleaner which is essentially quick dry electronic cleaner.

Many newer vehicles with fuel injection have an idle air control valve. These can/will become dirty and sticky over time and cause idling and stalling issues. Most can be removed and cleaned with a throttle body cleaner. A carbon fouled throttle body can cause poor idling and stalling as well.

Warnings

Working on your car can be dangerous. Don't attempt any of these fixes while the car is running.